ToEE for the tactics.
ToEE is an exploration and tactical combat game, with interaction tacked on to actually qualify as a modern RPG. Being based on the most sane incarnation of the D&D ruleset, it is the only game of the three that can actually aspire to be tactical, and it delivers. Story-wise, it follows the plot of a classic D&D module, which is to say, you've seen such a plot done and redone in hundreds of games since. Community patches are available, additional material is hard to come by.
BG for the strategy and the investment.
Let's face it: AD&D is less tactically interesting. The replayability of BG lies in the long and epic plot, a huge number of NPCs and it being highly moddable, that is, there's a lot of stuff that you can download for free and insert into the game. BG not being able to demand advanced tactics from the player, you can instead concern yourself with strategy, such as inviting and equipping characters, planning exploration (here be dragons; let's get a couple more levels under our belts and then proceed) and managing the cycle of combat-rest-shopping.
The story continues in BG2 (which is not on GOG as of this writing) - although you might experience a disconnect if your BG1 playthrough wasn't close to canonical, and several great characters do not make a reappearance. Thus, BG1 is an investment, and it will demand more investment, but the consensus is that it's worth your time and money.
PS:T for the roleplaying.
PS:T takes the CRPG conventions and turns them upside down, this is how it rises above the status of cult classic and becomes a timeless treasure and an outstanding achievement of the creative genius. While most games let you customize your character's name, appearance, gender, alignment and whatnot and then make you follow the beaten path, PS:T makes you play a character with a very distinctive - but fixed - appearance, NO NAME at all and unprecedented roleplaying options. Plus, if you so wish, you'll be accompanied by the awesomest party members ever - and yes, this is all part of the story.
The "good ending" of the story is very satisfying, but far from happy, even less happy are the bad endings, including a number of premature ones, which are outright horrifying. Did I mention that dying permanently is the win condition of the game?
However, the game lacks certain difficulty-increasing elements. It's likely you'll be too engrossed in the story to notice, but it's really obvious if you know what to look for. (Still, I reckon it would be impossible to get rid of the bad of AD&D and release a game based on a D&D setting in 1999.)
There's no planning advancement - PS:T breaks a number of rules in this regard, giving you attribute points with every level gained and the ability to switch classes in the middle of the game. No worrying about equipment: party members bring their own stuff, and in the few cases you find an upgrade, you know who's going to wield/wear it. No managing party composition except in a roleplaying sense: battles are really easy.
Now, all these could be viewed as advantages: not being distracted by the necessity to decorate your character like a Christmas tree, choosing companions you like as people instead of by combat effectiveness, selecting the dialogue options you feel like selecting instead of what brings moar XP, sheer power that can be ascribed to you remembering and invoking your former glory (as per the plot) instead of training from "this end is for stabbing" upwards.
The bad part is where story progress is based on Wisdom, Intelligence and in a lesser way Charisma, so you just have to be a wizard, invest heavily in the two former stats and have a Charisma-increasing spell up. Sure, "mundanes suck" can be also viewed as a moral and a plot point, but it's kinda heavy-handed.
Patches and content restoration packs are available.
Bottom line: epic - finished - happy, pick any two.
Post edited October 19, 2010 by Starmaker